The invention relates to an improved switch of the type shown in U.S. Pat. No. 3,965,755, and, more particularly, to a switch having an arrangement for permitting user pre-orientation of the rotatable control shaft.
The switch disclosed in U.S. Pat. No. 3,965,755 comprises a housing having supported therein a movable actuator and a rotatable selector shaft for positioning the actuator as a function of the rotational position of the shaft. An actuator driver is carried by the shaft and is operatively interconnected to the actuator to drive the same upon rotation of the driver by the shaft, the shaft and driver being axially movable relative to the actuator. Means are provided whereby the shaft cannot be rotated relative to the housing until the shaft is axially moved from a certain axial position thereof to another axial position thereof to clear the means thereby unlocking the selector shaft. The certain axial and rotational position of the selector shaft can be the "off" position of the selector shaft and the actuator can comprise a cam for operating a set of electrical contacts disposed in the housing of the control device. The housing has a latching part cooperable with a latching art of the shaft when the shaft is in a certain rotational and axial position relative to the housing whereby the shaft cannot be rotated relative to the housing until the shaft is axially moved from that certain axial position thereof to another axial position thereof to clear the latching part of the shaft from the latching of the housing and thereby unlock the selector shaft.
However, one problem with the switch of U.S. Pat. No. 3,965,755 is that it cannot be used as a replacement for a large variety of similar switches, but rather must be modified, during manufacture, to suit each replacement situation. This limitation results from the fact that the user of this switch does not have the ability to easily change the angular orientation of the control shaft relative to the housing when the device is in the "off" position. More specifically, after manufacture the "off" position of the shaft is fixed and this greatly reduces the versatility of the switch as a replacement vehicle. The reduction in versatility comes about because of the fact that the shaft is marked or keyed in some manner to a control knob to establish an "off" position and other similar switch operating positions. For this reason the shaft of the switch usually includes a flat portion at the operator end thereof. This flat portion the cooperates with a similar flat female receptacle on the control knob, which knob is imprinted with indicia to establish the "off" position and other control settings. It is thus easy to see that if older switches for a similar use have flat portions oriented in a variety of positions, such switches cannot all be replaced by a single fixed shaft switch without concurrent replacement of their associated control knobs.
Since it is uneconomical and impractical to provide the vast combinations of knobs required to solve the problem with knob replacement, the more desirable solution is to provide a switch having a user variable control shaft orientation.